Method and device for determining timer configuration

ABSTRACT

Embodiments of the disclosure generally relate to determining configuration of a DRX timer. A wireless device determines a relationship between a DRX timer and different scheduling units and determines a time unit of the DRX timer based on the determined relationship. Then, the wireless device calculates a time interval indicated by the DRX timer based on the time unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 15/774,278,filed May 7, 2018, which is the National Stage of InternationalApplication No. PCT/CN2018/079561, filed Mar. 20, 2018, which claimspriority to International Application No. PCT/CN2017/077915, filed Mar.23, 2017, which are hereby incorporated by reference.

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to the field ofcommunications, and more particularly, to a method and device fordetermining configuration of a discontinuous reception (DRX) timer.

BACKGROUND ART

Conventionally, in Long Term Evolution (LTE), when user equipment (UE)is configured with discontinuous reception, there are quite severaltimers need be configured to make the discontinuous reception work. Thetimers associated with DRX may be collectively referred to as DRX timersand may include, for example, onDurationTimer, drx-InactivityTimer,drx-RetransmissionTimer, and so on. In LTE, time units for all the DRXtimers are the same as the scheduling unit, that is, a subframe or aTransmission Time Interval (TTI) having a time length of 1 ms.

In the next generation network, for instance, in New Radio (NR), the UEneeds to support DRX as well and quite probably uses a DRX mechanismsimilar as in LTE. In other words, there may be quite several DRX timersneed be configured to make DRX work in NR. Different from LTE, NR needssupport different numerologies and/or TTI lengths. The absolute timedurations of different numerologies/TTI lengths are different. By way ofexample, for a numerology of 15 kHz sub-carrier spacing (SCS), thecorresponding TTI length is 1 ms. For a numerology of 30 kHz SCS, itsTTI length is 0.5 ms.

For NR, a TTI may have a shorter transmission duration which comprisesless Orthogonal Frequency Division Multiplexing (OFDM) symbols than anormal TTI comprising 14 OFDM symbols. For instance, a UE may beconfigured to be scheduled in slots comprising 7 OFDM symbols instead ofin a normal TTI comprising 14 OFDM symbols. An even shorter slot may beused as well, for example, a mini-slot including 2 OFDM symbols.

If the DRX timer in NR is configured in the same way as in LTE, i.e. thetime unit for all timers is set according to the same TTI length, itwould cause some confusion. More specifically, since the scheduling unitfor the numerology of 15 kHz is 1 ms while the scheduling unit for thenumerology of 30 kHz is 0.5 ms, if a DRX timer has a value of 5, itindicates 5 ms for a numerology of 15 kHz but indicates 2.5 ms for anumerology of 30 kHz. In such case, the UE may be unclear about the timeinterval actually indicated by the DRX timer, when the DRX timer shouldbe active, or when the DRX timer should be sleep. This would cause amismatching issue between the network (NW) side and the UE. For example,the UE may miss the scheduling from the NW when it is sleeping but theNW thinks it is active, or may waste its power when it is actuallyactive but the NW thinks it is sleeping. As such, transmissionefficiency and network performance would be reduced.

SUMMARY OF THE INVENTION

In general, embodiments of the present disclosure provide a solution forsolving the DRX timer mismatching issue as discussed above.

In a first aspect, a method implemented at a wireless device isprovided. The wireless device determines a relationship between a DRXtimer and different scheduling units and determines a time unit of theDRX timer based on the determined relationship. Then, the wirelessdevice calculates a time interval indicated by the DRX timer based onthe time unit. The corresponding computer program is also provided.

In one embodiment, determining the relationship of the DRX timer anddifferent scheduling units may comprise: determining whether the DRXtimer needs to be aligned with respect to the different schedulingunits.

In one embodiment, determining the time unit of the DRX timer maycomprise: in response to determining that the DRX timer needs to bealigned with respect to the different scheduling units, performing atleast one of: determining the time unit of the DRX timer as a predefinedvalue; determining the time unit of the DRX timer based on a predefinednumerology; determining the time unit of the DRX timer based on acurrently used numerology; and determining the time unit of the DRXtimer based on an indication received from a network device, theindication indicating a value of the time unit configured by the networkdevice.

In one embodiment, determining the time unit of the DRX timer based on acurrently used numerology may comprise: obtaining information aboutnumerologies used by a primary cell and a secondary cell of the wirelessdevice; and determining the time unit of the DRX timer based on thenumerology used by the primary cell.

In one embodiment, determining the time unit of the DRX timer maycomprise: in response to determining that the DRX timer does not need tobe aligned with respect to the different scheduling units, obtaininginformation about numerologies used by different carriers; anddetermining time units of the DRX timer for the different carriers basedon the numerologies.

In one embodiment, determining the time unit of the DRX timer maycomprise: in response to determining that the DRX timer does not need tobe aligned with respect to the different scheduling units, obtaininginformation about scheduling units used by different Hybrid AutomaticRepeat request (HARQ) processes; and determining time units of the DRXtimer for the different HARQ processes based on the information aboutscheduling units.

In one embodiment, determining the time unit of the DRX timer maycomprise: in response to determining that the DRX timer does not need tobe aligned with respect to the different scheduling units, obtaininginformation about scheduling units used by different HARQ transmissionsin a HARQ process; and determining time units of the DRX timer for thedifferent HARQ transmissions based on the information about schedulingunits.

In a second aspect, an apparatus implemented at a wireless device isprovided. The apparatus includes a determining unit and a calculatingunit. The determining unit is configured to determine a relationshipbetween a DRX timer and different scheduling units, and determine a timeunit of the DRX timer based on the determined relationship. Thecalculating unit is configured to calculate a time interval indicated bythe DRX timer based on the time unit.

In a third aspect, a wireless device is provided. The wireless deviceincludes: a processor and a memory. The memory contains instructionsexecutable by the processor, whereby the processor being adapted tocause the wireless device to perform the method according to the firstaspect of the present disclosure.

According to embodiments of the present disclosure, the wireless devicedetermines a time unit of the DRX timer according to its relationshipwith respect to different scheduling units. As such, there would be acommon understanding between a network device and a terminal device ofthe time duration indicated by the DRX timer when the UE supportsmultiple numerologies/TTI lengths. Communication between the networkdevice and the terminal device can be performed based on the commonunderstanding of the DRX timer. In this way, transmission efficiency andnetwork performance can be effectively improved.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and benefits of variousembodiments of the disclosure will become more fully apparent, by way ofexample, from the following detailed description with reference to theaccompanying drawings, in which like reference numerals or letters areused to designate like or equivalent elements. The drawings areillustrated for facilitating better understanding of the embodiments ofthe disclosure and not necessarily drawn to scale, in which:

FIG. 1 shows a schematic diagram 100 of a wireless communicationnetwork;

FIG. 2 shows a flowchart of a method 200 of determining configuration ofa DRX timer in accordance with an embodiment of the present disclosure;

FIG. 3 shows a flowchart of a method 300 of determining configuration ofa DRX timer in accordance with an embodiment of the present disclosure;

FIG. 4A shows a diagram 400 of configuration of a DRX timer fordifferent carriers using different numerologies according to the priorart;

FIG. 4B shows a diagram 410 of configuration of a DRX timer fordifferent carriers using different numerologies in accordance with anembodiment of the present disclosure;

FIG. 5 shows a block diagram of an apparatus 500 implemented at awireless device in accordance with an embodiment of the presentdisclosure; and

FIG. 6 shows a simplified block diagram 600 of a wireless device that issuitable for use in implementing embodiments of the present disclosure.

DETAILED DESCRIPTION

The present disclosure will now be discussed with reference to severalexample embodiments. It should be understood that these embodiments arediscussed only for the purpose of enabling those skilled persons in theart to better understand and thus implement the present disclosure,rather than suggesting any limitations on the scope of the presentdisclosure.

As used herein, the term “wireless communication network” refers to anetwork following any suitable communication standards, such asLTE-Advanced (LTE-A), LTE, Wideband Code Division Multiple Access(WCDMA), High-Speed Packet Access (HSPA), and so on. Furthermore, thecommunications between a terminal device and a network device in thewireless communication network may be performed according to anysuitable generation communication protocols, including, but not limitedto, the first generation (1G), the second generation (2G), 2.5G, 2.75G,the third generation (3G), the fourth generation (4G), 4.5G, the futurefifth generation (5G) communication protocols, and/or any otherprotocols either currently known or to be developed in the future.

The term “wireless device” refers to a network device or a terminaldevice in a wireless communication network.

The term “network device” refers to a device in a wireless communicationnetwork via which a terminal device accesses the network and receivesservices therefrom. The network device refers a base station (BS), anaccess point (AP), a Mobile Management Entity (MME),Multi-cell/Multicast Coordination Entity (MCE), a gateway, a server, acontroller or any other suitable device in the wireless communicationnetwork. The BS may be, for example, a node B (NodeB or NB), an evolvedNodeB (eNodeB or eNB), a Remote Radio Unit (RRU), a radio header (RH), aremote radio head (RRH), a relay, a low power node such as a femto, apico, and so forth.

Yet further examples of network device include multi-standard radio(MSR) radio equipment such as MSR BSs, network controllers such as radionetwork controllers (RNCs) or base station controllers (BSCs), basetransceiver stations (BTSs), transmission points, transmission nodes,Multi-cell/multicast Coordination Entities (MCEs), core network nodes(e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes(e.g., E-SMLCs), and/or MDTs. More generally, however, network devicemay represent any suitable device (or group of devices) capable,configured, arranged, and/or operable to enable and/or provide aterminal device access to the wireless communication network or toprovide some service to a terminal device that has accessed the wirelesscommunication network.

The term “terminal device” refers to any end device that can access awireless communication network and receive services therefrom. By way ofexample and not limitation, the terminal device refers to a mobileterminal, UE, or other suitable device. The UE may be, for example, aSubscriber Station (SS), a Portable Subscriber Station, a Mobile Station(MS), or an Access Terminal (AT). The terminal device may include, butnot limited to, portable computers, image capture terminal devices suchas digital cameras, gaming terminal devices, music storage and playbackappliances, a mobile phone, a cellular phone, a smart phone, a tablet, awearable device, a personal digital assistant (PDA), a vehicle, and thelike.

The terminal device may support device-to-device (D2D) communication,for example by implementing a 3GPP standard for sidelink communication,and may in this case be referred to as a D2D communication device.

As yet another specific example, in an Internet of Things (IOT)scenario, a terminal device may represent a machine or other device thatperforms monitoring and/or measurements, and transmits the results ofsuch monitoring and/or measurements to another terminal device and/or anetwork equipment. The terminal device may in this case be amachine-to-machine (M2M) device, which may in a 3GPP context be referredto as a machine-type communication (MTC) device. As one particularexample, the terminal device may be a UE implementing the 3GPP narrowband internet of things (NB-IoT) standard. Particular examples of suchmachines or devices are sensors, metering devices such as power meters,industrial machinery, or home or personal appliances, e.g.refrigerators, televisions, personal wearables such as watches etc. Inother scenarios, a terminal device may represent a vehicle or otherequipment that is capable of monitoring and/or reporting on itsoperational status or other functions associated with its operation.

As used herein, the singular forms “a” and “an” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “has,” “having,”“includes” and/or “including” as used herein, specify the presence ofstated features, elements, and/or components and the like, but do notpreclude the presence or addition of one or more other features,elements, components and/or combinations thereof. The term “based on” isto be read as “based at least in part on.” The term “one embodiment” and“an embodiment” are to be read as “at least one embodiment.” The term“another embodiment” is to be read as “at least one other embodiment.”Other definitions, explicit and implicit, may be included below.

Now some exemplary embodiments of the present disclosure will bedescribed below with reference to the figures. Reference is first madeto FIG. 1, which shows a schematic diagram 100 of a wirelesscommunication network. There illustrates a network device 101 and aterminal device 102 in the wireless communication network.

It is to be understood that the configuration of FIG. 1 is describedmerely for the purpose of illustration, without suggesting anylimitation as to the scope of the present disclosure. Those skilled inthe art would appreciate that the wireless communication network 100 mayinclude any suitable number of terminal devices and/or network devicesand may have other suitable configurations. In some embodiments, thenetwork device 101 may communicate with one or more terminal devicesother than the terminal device 102.

In the wireless communication network shown in FIG. 1, the concept ofdiscontinuous reception (DRX) is employed for saving power. DRX can beused to enable a wireless device, such as the terminal device 102, todiscontinuously monitor a control channel, such as the physical downlinkcontrol channel (PDCCH) communicated from a transmission station such asthe network device 101. The discontinuous monitoring can providesignificant power savings at the terminal device 102 since the receiverat the terminal device 102 can be turned off.

Conventionally, time units for all DRX timers are the same as thescheduling unit, that is, a subframe or a TTI having a time length of 1ms. However, if a wireless device supports a plurality of numerologiesand/or scheduling units, the wireless device may be unclear about timeintervals actually indicated by the DRX timers, respectively. Thenetwork device and the terminal device cannot have a commonunderstanding of the time duration indicated by the same DRX timer. Assuch, the mismatching issue of the DRX timer occurs, and transmissionefficiency and network performance are reduced.

In order to solve the above and other potential problems, embodiments ofthe present disclosure provide solutions for solving the DRX timermismatching issue. In the proposed solution, a wireless devicedetermines relationship between a DRX timer and different schedulingunits (that is, different TTI lengths). From the relationship, thewireless device may understand whether the DRX timer needs to be alignedwith respect to the different scheduling units. Then the wireless devicedetermines a time unit of a DRX timer based on the relationship, andcalculates the time interval indicated by the DRX timer based on thetime unit. In this way, it is possible to reach a common understandingbetween a network device and a terminal device of the time durationindicated by the DRX timer when the UE supports multiplenumerologies/TTI lengths. As such, communication between the networkdevice and the terminal device can be performed based on the commonunderstanding of the DRX timer.

More details of embodiments of the present disclosure will be discussedwith reference to FIGS. 2 to 6 below. FIG. 2 shows a flowchart of amethod 200 of transmitting downlink control information in accordancewith an embodiment of the present disclosure. With the method 200, theabove and other potential deficiencies in the conventional approachescan be overcome. It would be appreciated by those skilled in the artthat the method 200 may be implemented by a wireless device, such as anetwork device 101, a terminal device 102, or other suitable devices.

The method 200 is entered at 210, where the wireless device determines arelationship between a DRX timer and different scheduling units. Thedifferent scheduling units are associated with a plurality ofnumerologies. The numerology indicates a frequency spacing configurationof subcarrier in wireless communication system. The DRX timer asdiscussed may include a variety of timers associated with DRX, forexample, but not limited to, onDurationTimer, drx-InactivityTimer,drx-RetransmissionTimer, longDRX-CycleStartOffset, shortDRX-Cycle,drxShortCycleTimer, drx-ULRetransmissionTimer, HARQ RTT timer, UL HARQRTT timer, and so on. It is understood that a time unit of a DRX timermay be the same as or different from the time unit of another DRX timer.

In some embodiments, the relationship between the DRX timer and thedifferent scheduling units may indicate whether the DRX timer needs tobe aligned with respect to the different scheduling units. Thus, at 210,the wireless device may determine whether the DRX timer needs to bealigned with respect to the different scheduling units. In embodimentsof the present disclosure, when DRX timers are related to a Media AccessControl (MAC) entity which is shared by different schedulingunits/numerologies, it may be determined that these DRX timers need tobe aligned to enable the network device and the terminal device to reacha common understanding about the DRX timers, so as to simplify theeffort at both of the network device and the terminal device to maintainDRX related timers.

As for DRX timers such as onDurationTimer, drx-InactivityTimer,drxShortCycleTimer, shortDRX-Cycle, and longDRX-CycleStartOffset, whichare used to define per MAC entity behavior and are irrelevant todifferent scheduling units/numerologies, it may be determined that theseDRX timer need to be aligned with respect to different scheduling unitsto define per MAC entity behavior.

As for the DRX timers such as drx-RetransmissionTimer,drx-ULRetransmissionTimer, HARQ RTT timer, and UL HARQ RTT timer, sincethey are used to define per transmission per HARQ process behaviorwithin a UE, and since different carriers using different numerologiesshare one MAC entity in carrier aggregation (CA) but using differentHARQ entities, it is reasonable to not align these timers to define HARQbehavior.

In some embodiments, it may be determined that onDurationTimer,drx-InactivityTimer, drxShortCycleTimer, shortDRX-Cycle, andlongDRX-CycleStartOffset belong to a first group which needs be aligned,which means that the time units of these DRX timers are independent ondifferent scheduling units associated with different numerologies, whiledrx-RetransmissionTimer, drx-ULRetransmissionTimer, HARQ RTT timer, andUL HARQ RTT timer belong to a second group which does not need bealigned, which means that the time units of these DRX timers aredependent on different scheduling units associated with differentnumerologies.

At 220, the wireless device determines a time unit of the DRX timerbased on the determined relationship.

In some embodiments, if the DRX timer belongs to the first group, suchas onDurationTimer, drx-InactivityTimer, drxShortCycleTimer,shortDRX-Cycle, or longDRX-CycleStartOffset, it may be determined fromthe relationship that the DRX timer needs to be aligned with respect tothe different scheduling units. In this case, the wireless device maydetermine the time unit of the DRX timer as a predefined value. Thepredefined value may be an absolute value, for example, 1 ms, which isirrelevant to the numerologies. Thus, when onDurationTimer is set to 5,it means that the wireless device may be active for 5 ms in on Duration.

Alternatively, the wireless device may determine the time unit of theDRX timer based on a predefined numerology. The predefined numerologymay be a fixed reference numerology that is irrelevant to thenumerologies currently used by the wireless device. For example,assuming the predefined numerology for Synchronization Signal (SS) blocktransmission has a subcarrier spacing of 15 kHz, even a wireless deviceis currently using a numerology having a subcarrier spacing of 30 kHz(also referred to as “a 30 kHz numerology” hereafter), whenonDurationTimer is set to 5, it can be determined that the time unit is1 ms corresponding to the 15 kHz numerology, instead of 0.5 mscorresponding to the 30 kHz numerology. As such, it may be determinedthat the DRX timer indicates that the wireless device will be active for5 ms, instead of 2.5 ms.

As a further alternative, the wireless device may determine the timeunit of the DRX timer based on a currently used numerology. In thiscase, the wireless device may obtain information about numerologies usedby a primary cell (PCell) and a secondary cell (SCell) of the wirelessdevice, and determine the time unit of the DRX timer based on thenumerology used by the primary cell. In this way, the time unit can bedetermined dynamically according to the current used numerology. By wayof example, assuming a UE is currently using both 15 kHz and 30 kHznumerologies and the PCell is using the 15 kHz numerology, then the timeunit is determined according to the 15 kHz numerology. Thus, whenonDurationTimer is set to 5, it can be determined that the time unit is1 ms corresponding to the 15 kHz numerology, and the UE will be activefor 5 ms. If later the UE uses a 30 kHz numerology in PCell and a 60 kHznumerology in SCell, then it can be determined that the time unit is 0.5ms corresponding to the 30 kHz numerology, and the UE will be active for2.5 ms.

As a still further alternative, the wireless device may determine thetime unit of the DRX timer based on an indication configured by andreceived from a network device. In this case, the wireless device may bea terminal device and may send a request for configuration of the timeunit to the network device. The network device may configure the timeunit for the DRX timer and send it to the terminal device via anindication. The indication may be transmitted in any suitable message orsignaling, such as a Radio Resource Control (RRC) signaling. Theindication may indicate a value of the time unit configured by thenetwork device. Thus, the terminal device may determine the time unit ofthe DRX timer as the value indicated by the indication.

In addition to the above embodiments, if the DRX timer is for exampledrx-RetransmissionTimer, drx-ULRetransmissionTimer, HARQ RTT timer, orUL HARQ RTT timer, it may be determined that the DRX timer does not needto be aligned with respect to the different scheduling units. In thiscase, the DRX timer is bundled to the numerologies/TTI lengths scheduledby the wireless device. A same value may be configured for a DRX timerwith respect to different numerologies/TTI lengths, but the time unit ofthe DRX timer may be interpreted differently depending on thenumerology/TTI duration that is currently used by the wireless device.

In an embodiment, the time unit may be determined per carrier. That is,the DRX timers may be interpreted differently for different carriersusing different numerologies. In particular, the wireless device mayobtain information about numerologies used by different carriers, anddetermine time units of the DRX timer for the different carriers basedon the numerologies. In an example, a UE is using carrier aggregation oftwo carriers, a 15 kHz numerology being used in carrier C1 and a 30 kHznumerology being used in carrier C2. If the DRX timer, for example,drx-RetransmisisonTimer, is set to 4, it may be determined that the timeunit of the DRX timer is 1 ms for carrier C1. Thus, it can be determinedthat the DRX timer indicates a time interval of 4 ms for a HARQ processin carrier C1. On the other hand, for a HARQ process in C2, it may bedetermined that the time unit of the DRX timer is 0.5 ms, and the DRXtimer indicates a time interval of 2 ms.

In a further embodiment, the time unit may be determined per HybridAutomatic Repeat request (HARQ) process. In other words, the DRX timermay be interpreted differently for different HARQ processes in one HARQentity. That is, a time unit of a DRX timer may be dependent on aconfiguration of a scheduling unit associated with a HARQ process indifferent HARQ processes. More specifically, the wireless device mayobtain information about scheduling units used by different HARQprocesses, and determine time units of the DRX timer for the differentHARQ processes based on the information about scheduling units. In anexample, a UE is scheduled with different TTI lengths for different HARQprocesses in one carrier. Assuming that SCS is 15 kHz (that is, a 15 kHznumerology) and the DRX timer (for example, drx-RetransmisisonTimer) isset to 4, if the UE has a scheduling unit of 7 OFDM symbols for HARQprocess ID 1, which is a half of the LTE scheduling unit including 14OFDM symbols, then the time unit of the DRX timer may be determined as ahalf of the subframe length, namely, 0.5 ms. As such, the DRX timerindicates a time interval of 2 ms for HARQ process ID 1. If the UE isscheduled with a 14-OFDM symbol TTI on HARQ process ID 2, the time unitof the DRX timer may be determined as 1 ms and the DRX timer indicates atime interval of 4 ms for HARQ process ID 2.

In a still further embodiment, the time unit may be determined per HARQtransmission of a HARQ process from different HARQ processes, whichmeans that the time unit of DRX timer may be dependent on aconfiguration of a HARQ retransmission in the HARQ process. In otherwords, the DRX timers may be interpreted differently for different HARQtransmission attempts in one HARQ process of one HARQ entity. Morespecifically, the wireless device may obtain information aboutscheduling units used by different HARQ transmissions in a HARQ process,and determine time units of the DRX timer for the different HARQtransmissions based on the information about scheduling units. In anexample, if a UE is scheduled with different scheduling units (i.e., TTIlengths) for the same HARQ process in one carrier. If the UE is using a15 kHz numerology and the DRX timer (e.g., drx-RetransmisisonTimer) isset to 4, and if the UE is scheduled with a 7-OFDM symbol initialtransmission for a HARQ process ID 1, the time unit of the DRX timer maybe determined as a half of the subframe length, namely, 0.5 ms. As such,the DRX timer indicates a time interval of 2 ms for the initialtransmission of the HARQ process ID 1. If later the UE is rescheduledwith a 14-OFDM symbol TTI for retransmission of the same HARQ process ID1, the time unit of the DRX timer may be determined as 1 ms and the DRXtimer indicates a time interval of 4 ms for the retransmission of theHARQ process ID 1.

At 230, the wireless device calculates a time interval indicated by theDRX timer based on the time unit. According to embodiments of thepresent disclosure, the time interval may be calculated by multiplex thevalue of the DRX timer, for example, a numerical value of 4, and thetime unit of the DRX timer, for example, 1 ms. Thus, the time intervalcan be calculated as 4 ms.

It is to be understood that this example is illustrated for discussion,rather than suggesting any limitation. Those skilled in the art wouldappreciate that there are many other ways for calculating the timeinterval based on the time unit. For example, the calculation may beperformed by introducing a weight or a factor predefined according tosystem requirements, standards or specifications, network conditions,and/or the like.

In view of the forgoing, for a DRX timer in the first group, thewireless device may interpret the DRX timer as a single value which isthe same for all numerologies used by the wireless device. For the DRXtimer in the second group, the wireless device may interpret the DRXtimer as multiple values which are different for different numerologiesused by the wireless device.

Compared with the conventional solutions, by determining a time unit ofa DRX timer based on the relationship between the DRX timer anddifferent scheduling units, it is possible to reach a commonunderstanding between a network device and a terminal device of the timeduration indicated by the DRX timer when multiple numerologies/TTIlengths are supported. As such, communication between the network deviceand the terminal device can be performed based on the commonunderstanding of the DRX timer. As a result, transmission efficiency andnetwork performance can be effectively improved.

FIG. 3 shows a flowchart of a method 300 of determining configuration ofa DRX timer in accordance with an embodiment of the present disclosure.The method 300 may be considered as further implementations of themethod 200. In the embodiment described with respect to FIG. 3, if theDRX timer needs to be aligned with respect to the different schedulingunits, the wireless device determines the time unit of the DRX timerbased on a numerology currently used in PCell. Otherwise, the wirelessdevice determines the time unit for different carriers using differentnumerologies. It is to be understood that the method 300 are justdescribed for example, rather than suggesting any limitations.

At 310, it is determined whether the DRX timer needs to be aligned withrespect to the different scheduling units. If yes, the method 300proceeds to 320, where the wireless device obtains information aboutnumerologies used by a primary cell and a secondary cell of the wirelessdevice. At 330, the wireless device determines the time unit of the DRXtimer based on the numerology used in the PCell.

On the other hand, if the DRX timer does not need to be aligned withrespect to the different scheduling units, the wireless device obtainsinformation about numerologies used by different carriers at 340. At350, the wireless device determines time units of the DRX timer for thedifferent carriers based on the numerologies.

At 360, the wireless device calculates a time interval indicated by theDRX timer based on the time unit. This block is similar as the block 230and thus details are omitted.

In this way, the DRX timer may be classified in two groups and thewireless device may interpret the DRX timer differently according towhich group it belongs to. For the first group, the wireless device mayinterpret it as having the same absolute time interval across multiplenumerologies/scheduling units. For the second group, the wireless devicemay interpret it as having different absolute time intervals acrossmultiple numerologies/scheduling units.

To better understand embodiments of the present disclosure, comparisonis made between solutions of the prior art and embodiments of thepresent disclosure as follows. FIG. 4A shows a diagram 400 ofconfiguration of a DRX timer for different carriers using differentnumerologies according to the prior art. As shown in FIG. 4A, there arethree carriers C1, C2 and C3 using three different numerologies, namely,15 kHz, 30 kHz and 60 kHz, respectively. In the example of FIG. 4A, whendifferent carriers using different numerologies, the DRX timer ofcarriers C1, C2 and C3 has different On durations 401, 403 and 405,respectively, and different Sleep durations 402, 404 and 406,respectively. This would either cause a mismatching issue because thenetwork device and the terminal device cannot have a commonunderstanding about the DRX timer of carriers C1, C2 and C3, or causemore power consumption at the terminal device when the terminal deviceneeds to operate DRX on a per carrier base not per MAC entity base.

FIG. 4B shows a diagram 410 of configuration of a DRX timer fordifferent carriers using different numerologies in accordance with anembodiment of the present disclosure. In the example of FIG. 4B, whendifferent carriers C1, C2 and C3 using different numerologies, the DRXtimer of carriers C1, C2 and C3 has the same On durations 411, 413 and415, respectively, and the same Sleep durations 412, 414 and 416,respectively. Thus, a common understanding of the DRX timer may beachieved for different carriers according to embodiments of the presentdisclosure.

Now reference is made to FIG. 5, which shows a block diagram of anapparatus 500 in accordance with an embodiment of the presentdisclosure. It would be appreciated that the apparatus 500 may beimplemented at a wireless device, for example, the network device 101,the terminal device 102, or any other suitable device.

As shown, the apparatus 500 includes a determining unit 510 and acalculating unit 520. The determining unit 510 is configured to:determine a relationship between a DRX timer and different schedulingunits, and determine a time unit of the DRX timer based on thedetermined relationship. The calculating unit 520 is configured tocalculate a time interval indicated by the DRX timer based on the timeunit.

In an embodiment, the determining unit 510 may be further configured to:determine whether the DRX timer needs to be aligned with respect to thedifferent scheduling units.

In an embodiment, the determining unit 510 may be further configured to:in response to determining that the DRX timer needs to be aligned withrespect to the different scheduling units, performing at least one of:determine the time unit of the DRX timer as a predefined value;determine the time unit of the DRX timer based on a predefinednumerology; determine the time unit of the DRX timer based on acurrently used numerology; and determine the time unit of the DRX timerbased on an indication received from a network device, the indicationindicating a value of the time unit configured by the network device.

In an embodiment, the determining unit 510 may be further configured to:obtain information about numerologies used by a primary cell and asecondary cell of the wireless device; and determine the time unit ofthe DRX timer based on the numerology used by the primary cell.

In an embodiment, the determining unit 510 may be further configured to:in response to determining that the DRX timer does not need to bealigned with respect to the different scheduling units, obtaininformation about numerologies used by different carriers; and determinetime units of the DRX timer for the different carriers based on thenumerologies.

In an embodiment, the determining unit 510 may be further configured to:in response to determining that the DRX timer does not need to bealigned with respect to the different scheduling units, obtaininformation about scheduling units used by different Hybrid AutomaticRepeat request, HARQ, processes; and determine time units of the DRXtimer for the different HARQ processes based on the information aboutscheduling units.

In an embodiment, the determining unit 510 may be further configured to:in response to determining that the DRX timer does not need to bealigned with respect to the different scheduling units, obtaininformation about scheduling units used by different Hybrid AutomaticRepeat request, HARQ, transmissions in a HARQ process; and determinetime units of the DRX timer for the different HARQ transmissions basedon the information about scheduling units.

It should be appreciated that components included in the apparatus 500correspond to the operations of the methods 200-300. Therefore, alloperations and features described above with reference to FIGS. 2-3 arelikewise applicable to the components included in the apparatus 500 andhave similar effects. For the purpose of simplification, the detailswill be omitted.

The components included in the apparatus 500 may be implemented invarious manners, including software, hardware, firmware, or anycombination thereof. In one embodiment, one or more units may beimplemented using software and/or firmware, for example,machine-executable instructions stored on the storage medium. Inaddition to or instead of machine-executable instructions, parts or allof the components included in the apparatus 500 may be implemented, atleast in part, by one or more hardware logic components. For example,and without limitation, illustrative types of hardware logic componentsthat can be used include Field-programmable Gate Arrays (FPGAs),Application-specific Integrated Circuits (ASICs), Application-specificStandard Products (ASSPs), System-on-a-chip systems (SOCs), ComplexProgrammable Logic Devices (CPLDs), and the like.

In accordance with embodiments of the present disclosure, there isprovided an apparatus implemented at a wireless device. The apparatusincludes: means for determining a relationship between a discontinuousreception, DRX, timer and different scheduling units; means fordetermining a time unit of the DRX timer based on the determinedrelationship; and means for calculating a time interval indicated by theDRX timer based on the time unit.

In an embodiment, the means for determining the relationship of the DRXtimer and different scheduling units comprises: means for determiningwhether the DRX timer needs to be aligned with respect to the differentscheduling units.

In an embodiment, the means for determining the time unit of the DRXtimer comprises: means for, in response to determining that the DRXtimer needs to be aligned with respect to the different schedulingunits, performing at least one of: determining the time unit of the DRXtimer as a predefined value; determining the time unit of the DRX timerbased on a predefined numerology; determining the time unit of the DRXtimer based on a currently used numerology; and determining the timeunit of the DRX timer based on an indication received from a networkdevice, the indication indicating a value of the time unit configured bythe network device.

In an embodiment, the means for determining the time unit of the DRXtimer based on a currently used numerology comprises: means forobtaining information about numerologies used by a primary cell and asecondary cell of the wireless device; and means for determining thetime unit of the DRX timer based on the numerology used by the primarycell.

In an embodiment, the means for determining the time unit of the DRXtimer comprises: means for in response to determining that the DRX timerdoes not need to be aligned with respect to the different schedulingunits, obtaining information about numerologies used by differentcarriers; and means for determining time units of the DRX timer for thedifferent carriers based on the numerologies.

In an embodiment, the means for determining the time unit of the DRXtimer comprises: means for in response to determining that the DRX timerdoes not need to be aligned with respect to the different schedulingunits, obtaining information about scheduling units used by differentHybrid Automatic Repeat request, HARQ, processes; and means fordetermining time units of the DRX timer for the different HARQ processesbased on the information about scheduling units.

In an embodiment, the means for determining the time unit of the DRXtimer comprises: means for, in response to determining that the DRXtimer does not need to be aligned with respect to the differentscheduling units, obtaining information about scheduling units used bydifferent Hybrid Automatic Repeat request, HARQ, transmissions in a HARQprocess; and means for determining time units of the DRX timer for thedifferent HARQ transmissions based on the information about schedulingunits.

FIG. 6 shows a simplified block diagram of a wireless device 600 that issuitable for implementing embodiments of the present disclosure. Itwould be appreciated that the wireless device 600 may be implemented asat least a part of, for example, the network device 101 or the terminaldevice 102.

As shown, the wireless device 600 includes a communicating means 630 anda processing means 650. The processing means 650 includes a dataprocessor (DP) 610, a memory (MEM) 620 coupled to the DP 610. Thecommunicating means 630 is coupled to the DP 610 in the processing means650. The MEM 620 stores a program (PROG) 640. The communicating means630 is for communications with other devices, which may be implementedas a transceiver for transmitting/receiving signals.

In some embodiments, the processing means 650 may be configured todetermine a relationship between a discontinuous reception, DRX, timerand different scheduling units; determine a time unit of the DRX timerbased on the determined relationship; and calculate a time intervalindicated by the DRX timer based on the time unit.

The PROG 640 is assumed to include program instructions that, whenexecuted by the associated DP 610, enable the wireless device 600 tooperate in accordance with the embodiments of the present disclosure, asdiscussed herein with the methods 200-300. The embodiments herein may beimplemented by computer software executable by the DP 610 of thewireless device 600, or by hardware, or by a combination of software andhardware. A combination of the data processor 610 and MEM 620 may formprocessing means 650 adapted to implement various embodiments of thepresent disclosure.

The MEM 620 may be of any type suitable to the local technicalenvironment and may be implemented using any suitable data storagetechnology, such as semiconductor based memory devices, magnetic memorydevices and systems, optical memory devices and systems, fixed memoryand removable memory, as non-limiting examples. While only one MEM isshown in the wireless device 600, there may be several physicallydistinct memory modules in the wireless device 600. The DP 610 may be ofany type suitable to the local technical environment, and may includeone or more of general purpose computers, special purpose computers,microprocessors, digital signal processors (DSPs) and processors basedon multicore processor architecture, as non-limiting examples. Thewireless device 600 may have multiple processors, such as an applicationspecific integrated circuit chip that is slaved in time to a clock whichsynchronizes the main processor.

Generally, various embodiments of the present disclosure may beimplemented in hardware or special purpose circuits, software, logic orany combination thereof. Some aspects may be implemented in hardware,while other aspects may be implemented in firmware or software which maybe executed by a controller, microprocessor or other computing device.While various aspects of embodiments of the present disclosure areillustrated and described as block diagrams, flowcharts, or using someother pictorial representation, it will be appreciated that the blocks,apparatus, systems, techniques or methods described herein may beimplemented in, as non-limiting examples, hardware, software, firmware,special purpose circuits or logic, general purpose hardware orcontroller or other computing devices, or some combination thereof.

By way of example, embodiments of the present disclosure can bedescribed in the general context of machine-executable instructions,such as those included in program modules, being executed in a wirelessdevice on a target real or virtual processor. Generally, program modulesinclude routines, programs, libraries, objects, classes, components,data structures, or the like that perform particular tasks or implementparticular abstract data types. The functionality of the program modulesmay be combined or split between program modules as desired in variousembodiments. Machine-executable instructions for program modules may beexecuted within a local or distributed device. In a distributed device,program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may bewritten in any combination of one or more programming languages. Theseprogram codes may be provided to a processor or controller of a generalpurpose computer, special purpose computer, or other programmable dataprocessing apparatus, such that the program codes, when executed by theprocessor or controller, cause the functions/operations specified in theflowcharts and/or block diagrams to be implemented. The program code mayexecute entirely on a machine, partly on the machine, as a stand-alonesoftware package, partly on the machine and partly on a remote machineor entirely on the remote machine or server.

The above program code may be embodied on a machine readable medium,which may be any tangible medium that may contain, or store a programfor use by or in connection with an instruction execution system,apparatus, or device. The machine readable medium may be a machinereadable signal medium or a machine readable storage medium. The machinereadable medium may include but not limited to an electronic, magnetic,optical, electromagnetic, infrared, or semiconductor system, apparatus,or device, or any suitable combination of the foregoing. More specificexamples of the machine readable storage medium would include anelectrical connection having one or more wires, a portable computerdiskette, a hard disk, a random access memory (RAM), a read-only memory(ROM), an erasable programmable read-only memory (EPROM or Flashmemory), an optical fiber, a portable compact disc read-only memory(CD-ROM), an optical storage device, a magnetic storage device, or anysuitable combination of the foregoing.

In the context of this disclosure, the wireless device may beimplemented in the general context of computer system-executableinstructions, such as program modules, being executed by a computersystem. Generally, program modules may include routines, programs,objects, components, logic, data structures, and so on that performparticular tasks or implement particular abstract data types. Thewireless device may be practiced in distributed cloud computingenvironments where tasks are performed by remote processing devices thatare linked through a communications network. In a distributed cloudcomputing environment, program modules may be located in both local andremote computer system storage media including memory storage devices.

Further, while operations are depicted in a particular order, thisshould not be understood as requiring that such operations be performedin the particular order shown or in sequential order, or that allillustrated operations be performed, to achieve desirable results. Incertain circumstances, multitasking and parallel processing may beadvantageous. Likewise, while several specific implementation detailsare contained in the above discussions, these should not be construed aslimitations on the scope of the present disclosure, but rather asdescriptions of features that may be specific to particular embodiments.Certain features that are described in the context of separateembodiments may also be implemented in combination in a singleembodiment. Conversely, various features that are described in thecontext of a single embodiment may also be implemented in multipleembodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in language specificto structural features and/or methodological acts, it is to beunderstood that the present disclosure defined in the appended claims isnot necessarily limited to the specific features or acts describedabove. Rather, the specific features and acts described above aredisclosed as example forms of implementing the claims.

1. A method implemented at a wireless device, comprising: determining atime unit of a discontinuous reception (DRX) timer based on one of aplurality of different numerologies each indicating a frequency spacingconfiguration; and determining a value indicated by the DRX timer to bea duration of time for the DRX timer based on the time unit.
 2. Themethod of claim 1, wherein determining the time unit of the DRX timerbased on one of the plurality of different numerologies furthercomprises: obtaining information of one of a plurality of differentscheduling units based on one of the plurality of differentnumerologies; and determining the time unit of the DRX timer based onthe information of one of the plurality of different scheduling units.3. The method of claim 1, wherein the time unit of the DRX timer isassociated with a Hybrid Automatic Repeat request (HARQ) process in aplurality of HARQ processes.
 4. The method of claim 3, wherein theduration of time for the HARQ process is a multiple of the time unit. 5.The method of claim 1, wherein the time unit of the DRX timer isassociated with a retransmission of a HARQ process in a plurality ofHARQ processes.
 6. The method of claim 1, wherein the DRX timer is oneof: an HARQ round trip time (RTT) timer, a drx-RetransmissionTimer, andan uplink (UL) RetransmissionTimer.
 7. The method of claim 1, whereinthe plurality of different numerologies are associated with a respectiveplurality of carriers and the time unit of the DRX timer is associatedwith a carrier in the plurality of carriers.
 8. The method of claim 7,wherein the plurality of carriers includes a first and second carriermapping to a first and second frequency spacing respectively, andwherein a first time unit associated with the first carrier is amultiple of a second time unit associated with the second carrier whenthe second frequency spacing is the multiple of the first frequencyspacing.
 9. A wireless device, comprising: a processor, and a memorycoupled to the processor and storing instructions thereon, theinstructions, when executed by the processor, causing the wirelessdevice to perform actions, the actions comprising: determining a timeunit of a discontinuous reception (DRX) timer based on one of aplurality of different numerologies each indicating a frequency spacingconfiguration; and determining a value indicated by the DRX timer to bea duration of time for the DRX timer based on the time unit.
 10. Thewireless device of claim 9, wherein determining the time unit of the DRXtimer based on one of the plurality of different numerologies furthercomprises: obtaining information of one of a plurality of differentscheduling units based on one of the plurality of differentnumerologies; and determining the time unit of the DRX timer based onthe information of one of the plurality of different scheduling units.11. The wireless device of claim 9, wherein the time unit of the DRXtimer is associated with a Hybrid Automatic Repeat request (HARQ)process in a plurality of HARQ processes.
 12. The wireless device ofclaim 11, wherein the duration of time for the HARQ process is amultiple of the time unit.
 13. The wireless device of claim 9, whereinthe time unit of the DRX timer is associated with a retransmission of aHARQ process in a plurality of HARQ processes.
 14. The wireless deviceof claim 9, wherein the DRX timer is one of: an HARQ round trip time(RTT) timer, a drx-RetransmissionTimer, and an uplink (UL)RetransmissionTimer.
 15. The wireless device of claim 9, wherein theplurality of different numerologies are associated with a respectiveplurality of carriers and the time unit of the DRX timer is associatedwith a carrier in the plurality of carriers.
 16. The wireless device ofclaim 15, wherein the plurality of carriers includes a first and secondcarrier mapping to a first and second frequency spacing respectively,and wherein a first time unit associated with the first carrier is amultiple of a second time unit associated with the second carrier whenthe second frequency spacing is the multiple of the first frequencyspacing.
 17. A non-transitory machine-readable storage medium havinginstructions stored thereon, the instructions, when executed on at leastone processor, being capable of causing the at least one processor toperform: determining a time unit of a discontinuous reception (DRX)timer based on one of a plurality of different numerologies eachindicating a frequency spacing configuration; and determining a valueindicated by the DRX timer to be a duration of time for the DRX timerbased on the time unit.
 18. The non-transitory machine-readable storagemedium of claim 17, wherein determining the time unit of the DRX timerbased on one of the plurality of different numerologies includes:obtaining information of one of a plurality of different schedulingunits based on one of the plurality of different numerologies; anddetermining the time unit of the DRX timer based on the information ofone of the plurality of different scheduling units.
 19. Thenon-transitory machine-readable storage medium of claim 17, wherein thetime unit of the DRX timer is associated with a Hybrid Automatic Repeatrequest (HARQ) process in a plurality of HARQ processes.
 20. Thenon-transitory machine-readable storage medium of claim 17, wherein theplurality of different numerologies are associated with a respectiveplurality of carriers and the time unit of the DRX timer is associatedwith a carrier in the plurality of carriers.